Certain machines, such as gas turbines, power generating devices, etc., utilize fuel to power their operations. For example, a gas turbine may combust a fuel, such as natural gas, in order to rotate a turbine section and produce work. In certain industrial environments, one or more byproducts or discharges of other processes and/or systems may be utilized as fuel sources to power a turbine or other machine. These various fuel sources may be blended or mixed before they are provided to the machine. For example, in an iron mill, coke oven gas and blast furnace gas may be mixed in order to form a combined fuel source that is utilized to power a gas turbine.
In conventional systems, a first fuel with a relatively high heating value is typically added into a second fuel with a lower heating value, and the combined fuel is provided to a machine. For example, coke oven gas is typically added into blast furnace gas, and the combined gas is provided to a gas turbine. However, the conventional systems often mix the gases in a set ratio or provide relatively limited functionality for adjusting the mixture of the gases. Accordingly, during changes in the operating condition of the gas turbine, such as transient events and/or load changes, the combined gas may not satisfy the power requirements of the gas turbine even if a flow of the combined gas is increased. Additionally, a set ratio may utilize a greater quantity of a high heating value gas than is necessary for suitable operation of the turbine, thereby leading to higher fuel cost.
Accordingly, a need exists for improved systems and methods for controlling fuel mixing.